Crusader: Champion of the Dark One

This story is more of a hobby and this is my first time writing so don't expect too much also English isn't my first language. Jason is a 16 year old boy trying to get through life with a father who expects him to be perfect and a school where everyone kinda hates him and bullies him with the exception of his two friends Jessica and Isaac. When he is falsely accused of beaten up a student the only witness to the crime Jessica his friend testifies against him and he is expelled from school. On his way home feeling betrayed and thinking about how to explain this to his father he is summoned to a dark cave where a being offers for him to become the champion of the Dark One